Bitcoin Core source code provide short explanation about those configuration.
# Relay and mine data carrier transactions (default: 1)
#datacarrier=1
# Relay transactions creating non-P2SH multisig outputs (default: 1)
#permitbaremultisig=1
AFAIK it means,
1.
datacarrier=1 allows you broadcast transaction with OP_RETURN.
2.
permitbaremultisig=1 allows you to broadcast multi-signature transaction which use P2MS (Pay to Multi Signature).
Those are default behavior of Bitcoin Core, so i don't understand why other node would determine it as a spam.
Good question, and I’m watching for any answers.